Raphael Rossi Silva

Épocas de semeadura e desempenho agronômico de cultivares de soja

O objetivo deste trabalho foi avaliar o efeito de epocas de semeadura no desempenho agronomico de cultivares de soja em Sao Domingos, SC, e indicar as cultivares mais estaveis e adaptadas a cada epoca. O experimento foi conduzido durante dois anos agricolas (2008/2009 e 2009/2010), com seis cultivares e quatro epocas de semeadura (15/10, 15/11, 15/12 e 15/1), em delineamento experimental de blocos ao acaso, com tres repeticoes e parcelas com area util de 3,6 m². A metodologia AMMI (modelos de efeitos principais aditivos com interacao multiplicativa) foi utilizada para avaliar o desempenho produtivo das cultivares, e a GGE (genotipo e interacao genotipo x ambiente) para avaliar a adaptabilidade e a estabilidade das cultivares nas diferentes epocas de semeadura. Em ambos os anos agricolas, as semeaduras em 15/10 e 15/11 maximizaram o numero de vagens por planta, o numero de graos por vagem, a estatura das plantas, o numero de ramos, a massa de mil sementes e, consequentemente, a produtividade de graos. As cultivares de ciclo medio ou precoce com porte elevado sao mais adequadas para semeaduras tardias.

Adaptabilidade e estabilidade de cultivares de trigo em diferentes épocas de semeadura, no Paraná

The objective of this work was to identify the best sowing dates and to evaluate the adaptability and stability of wheat cultivars in two wheat growing regions of the state of Parana, Brazil. Seven cultivars were evaluated at Guarapuava and nine at Palotina as to grain yield, at four sowing seasons, in 2006, 2007 and 2008. The experimental design was a randomized complete block design, with four and three replicates, for Guarapuava and Palotina, respectively. The methodologies REML/BLUP and genotype main effect and genotype x environment interaction (GGE biplot) were used for adaptability and stability analysis, and the AMMI model was used to identify the best sowing dates. Sowing in July, at Guarapuava, and in April, at Palotina, maximized grain yield. The cultivars Safira, at Guarapuava, and CD 113, at Palotina, are stable, highly adapted and show high grain yield.

Métodos para análise de adaptabilidade e estabilidade em cultivares de trigo no estado do Paraná

This investigation had the objective to evaluate grain yield adaptability and stability of 17 wheat cultivars (Triticum aestivum L.) for Parana State, Brazil, occording to four different methods. The experiments were carried out in 2007, at different locations of Parana, in complete randomized blocks experimental design, with 4 replicates. The Wricke (1965) methodology indicates stable cultivars, independently of average yield. Eberhart and Russell (1966) and Cruz et al. (1989) methodologies were equally efficient to evaluate stability and indicate cultivars that are stable and also adapted to favorable and unfavorable environments. Lin and Binns (1988) methodology showed to be of easy interpretation and was efficient to indicate cultivars of high yield and with good stability, where more responsive materials showed a lesser Pi, and high negative correlation of Spearman between grain yields. It was concluded that LIN and BINNS methodology is very specific and when associated to Wi offers more assurance in recommending cultivars for high stability.

Análises biplot na avaliação de cultivares de trigo em diferentes níveis de manejo

The objective of this study was to evaluate the agronomic performance of wheat cultivars under different management levels. Experiments were carried out in Pato Branco (PR), within crop years 2008 and 2009. The experimental design was randomized blocks in factorial scheme, with three replicates. Treatments consisted in four levels of management, control (E1), traditional (E2) and optimized (E3 and E4), distinguished by level of chemical fertilization and by control of weeds, pests and diseases. Methodologies in AMMI and GGE biplot graphics were used for data analysis. The levels of management maximized the wheat yield, especially when meteorological features were not limiting. Adaptability showed difference among cultivars in the crop managements. The BRS Guamirim cultivar showed adaptability to levels E3 and E4 in crop year 2008, whereas it was associated to E1 and E2 in crop year 2009. Only the cultivars BRS Tangara (E1 and E2) and Pampeano (E3 and E4) kept association consistency to traditional and optimized levels, in both years. Biplot techniques are efficient to indicate more adapted cultivars to levels of crop management in wheat.

Análises Biplot: conceitos, interpretações e aplicações

A selecao e recomendacao de genotipos superiores sao dificultadas devido a ocorrencia da interacao genotipo e ambiente. Nesse contexto, as analises biplot tem sido cada vez mais utilizadas na analise de dados agronomicos, com interacoes de natureza complexa. Entretanto, as particularidades existentes no grafico biplot dificultam sua interpretacao, podendo induzir o pesquisador a erros. Assim, este artigo de revisao discute a aplicabilidade e a interpretacao grafica dos modelos AMMI (Additive Main effects and Multiplicative Interaction) e GGE biplot (genotype main effects + genotype environment interaction) destas analises no grafico biplot. Tambem, visa a desmistificar a necessidade de comparacao entre ambas as metodologias. Discute-se quanto a escolha da metodologia mais adequada, levando em consideracao a informacao requerida e os objetivos do pesquisador.

Aplicação foliar de aminoácidos e adubação nitrogenada de cobertura na cultura do milho safrinha

The objective of this study was to evaluate the foliar application of amino acids associated with the application of nitrogen as topdressing on yield performance and agronomic characteristics of corn, cultivated during the latter season. The experimental design was a randomized block design in a 4 x 4 factorial, with 4 repetitions. Four doses of nitrogen (0, 60, 120 and 180 kg ha-1) as urea were used and four doses of amino acids (0, 8, 16, and 24 L ha-1) were applied on leaves. The maize cultivar used was Pioneer 305 31H. The variables analysed were: leaf N content, plant height, ear height, stem diameter, ear length, number of kernel rows per ear, number of kernels per row, number of grains per spike, weight of 100 grains and yield. The amino acids did not alter the analysed variables. Nitrogen increased linearly the variables plant height, height of insertion of ear, number of grains per ear and number of kernels per row. The length of spike, thousand grain weight and grain yield response to nitrogen obtained under maximum doses of 135.3, 157 and 149.5 kg ha-1, respectively.